<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        body{
            background: #859373;
        }
        .container{
            display: flex;
        }
        .left-box{
            height: 500px;
            width: 400px;
            border: 2px solid #fff;
            margin: 100px;
        }
        .right-box{
            height: 500px;
            width: 400px;
            border: 2px solid #fff;
            margin: 100px;
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="left-box"></div>
        <div class="right-box"></div>
    </div>
</body>
</html>